RLE is an old technique being used for decades, as is known as
Run-Length-Encoding, which means that for repeating sequence of bytes,
we keep an indicator for the length of the sequence and only one sample
of it, to save storage space.
GIMP can generate lossless-compressed TGA images, with RLE compression
being used. It means that for a compressed image, the data is no longer
arranged in sequence of pixels, but a sequence of pixel packets.
There are two possible pixel packets:
- RLE packets, which are encoded with one byte for indicating the
run-length and another one pixel (3 bytes for TrueColor pixel), so
essentially in runtime, the TGA decoder will use the length to plot
the same pixel in multiple pixels of the output pixel bitmap.
- Raw packets, which are encoded with one byte as indicator for the
length of the whole pixel sequence and N-length pixel sequence
afterwards.
This is not used for any sort of compression by the TGA format, but
still needed to be supported for full compatibility with TGA images
that uses the RLE compression.
GIMP allows a user to export a TGA image with either of these possible
orientations, so we can easily support it by looking at the X origin and
Y origin values to determine where to put the pixels in the bitmap.
The file `limits.h` had definitions for x86. This PR removes these
definitions and fixes the upper limit for the type ssize_t which was
defined to be 0x7fffffff.
This will temporarily bloat the size of PrimitiveString as LibJS is
transitioned to use String throughout, but will make doing so piecemeal
much easier.
If USING_AK_GLOBALLY is not defined, the name IsLvalueReference might
not be available in the global namespace. Follow the pattern established
in LibTest to fully qualify AK types in macros to avoid this problem.
We don't need to call `can_read_line()` as the buffer will be populated
by `find_and_populate_until_any_of()`. The change is also beneficial as
the buffer will be populated until a candidate is found and not
necessarily a new line.
The search used to go through the buffer from the start, even if we just
appended a small number of bytes at the end. It now remembers the last
stop and resume the search from it.
This parameter allows to start searching after an offset. For example,
to resume a search.
It is unfortunately a breaking change in API so this patch also modifies
one user and one test.
The previously defined operator was swap-based. With the defaulted
implementation, both integers are now copied, but it doesn't matter as
only the `ByteBuffer` allocates memory (i.e. non-null integers values
won't affect the destruction).
The old approach was basically a linear scan, which is slower than a
hash map for the currently 303 elements, as evidenced by the new
benchmark in TestCSSIDSpeed.
Before: Completed benchmark 'value_id_from_string' in 3238ms
After: Completed benchmark 'value_id_from_string' in 193ms
